The greatest online bookmark manager that I've come across is from JungleMate.com
It's an online office/email service that is completely free, NO ADVERTISING whatsoever,
and provides some very versatile features:
lets you add bookmark the page that you're on to your account by simply clicking a web link in your favorites. It pops up a litle screen and you can then add it to your bookmark collection.. You may have to log in first, but once you do, you remain logged in (unless you close all the browsers and restart IE).
The bookmark manager works like your typical file folder setup, which is great for organizing subjects/categories.
Each bookmark listing consists of the URL, the title, and a note section.
There is a tool that will allow you to import and export IE and Netscape bookmarks.
Also, along with the bookmark manager, there is a comprehensive set of features you can use for general work:
Notepad
Tasks
Contacts
Companies (similar to contacts, but for businesses)
Schedule
and lastly, a file storage section (you don't get much, only 2mb, but thats enough to store some important docs).
BTW, all of the features I mention above also have exportable/importable functionality, where you can even select the fields to make sure the .CSV file will work with whatever it imports into.
Anyway, you ought to check it out, it has been a godsend for me, since I surf alot from many different locations..